(a) Field of the Disclosure
The present disclosure relates to an automatic transmission for a vehicle. More particularly, the present disclosure relates to a planetary gear train of an automatic transmission for a vehicle having advantages of, by minimal complexity, realizing ten forward speeds, thereby improving power delivery performance and fuel consumption due to multi-stages, and improving driving stability of a vehicle by utilizing a low rotation speed of an engine.
(b) Description of the Related Art
Generally, in the automatic transmission field, achieving more shift stages is a technology for maximizing fuel consumption and driving efficiency and has been researched. Recent increases in oil prices are triggering hard competition in enhancing fuel consumption of a vehicle.
In this sense, research on an engine has been undertaken to achieve weight reduction and to enhance fuel consumption by so-called downsizing. Research on an automatic transmission has also been performed to simultaneously provide better drivability and fuel consumption by achieving more shift stages.
In order to achieve more shift stages for an automatic transmission, the number of parts, particularly the number of planetary gear sets is typically increased and installability, production cost, weight, and power flow efficiency according to the total length of transmission is increased.
Therefore, in order to maximally enhance fuel consumption of an automatic transmission having more shift stages, it is important for better efficiency to be derived by a smaller number of parts.
In this respect, an eight-speed automatic transmission has been recently introduced, and a planetary gear train for an automatic transmission enabling more shift stages is continuously required.
However, the majority of general automatic transmissions having more than eight speeds include three to four planetary gear sets and five to seven control elements (friction elements), in this case, total length is increased, which has drawbacks of deteriorating installability.
As a result, a plural row structure which accommodates planetary gear sets has been adopted, or a dog clutch is applied in place of wet control elements. However, in this case, applicable structure is restricted and shift feel is deteriorated by applying the dog clutch.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the disclosure and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.